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Neurology Midterm STudy Guide Summer 2011. pathological Conditions that can impair content of consciousness w/effecting levels of consciousness .
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pathological Conditions that can impair content of consciousness w/effecting levels of consciousness • Focal brain lesions producing isolated disorders of language or memory and more diffuse, chronic pathologic processes causing widespread deterioration of mental function (Dementia) • Dementia-almost exact opposite of Acute Confusional State • Level of consciousness not impaired, except occasionally late in course • Course: Chronic; steadily progressive • Autonomic Hyperactivity: Absent • Prognosis: Usually irreversible
general areas of circulation to the brain and common associated results of insults • Middle Cerebral Artery: Supplies entire Lateral Aspect of Cortex • Anterior Cerebral Artery: Supplies entire Medial Aspect of Cortex • Posterior Cerebral Artery: Supplies Occipital Lobe • Blood Distribution • Lateral Aspect of Cortex supplies Head to Knee • Medial Aspect of Cortex supplies Knee on down
Common causes of dementia, both reversible and non-reversible • Non-Reversible • Alzheimer is the most common cause • Vascular dementia, next most common • Reversible • Normal pressure hydrocephalus • Intracranial mass lesions • Vitamin B12 deficiency • Hypothyroidism • Neurosyphilis • Page 46 table 1-23
Components of the clinical neurological examinationsAppendix B page 377 • Cognitive Function • Gait • Cranial Nerves • Motor System • Sensory System • Reflexes
Aphasia Defined appendix a • Impairments of the expression or understanding of language are traditionally divided into categories depending on the pattern of the language deficit and the site of damage. • Broca • Paucity of speech, loss of grammar, telegraphic • Hemiparesis • Frontal lobe • Wernicke • Intact grammar, neologism, paraphasias, “word salad,” no comprehension • Visual field cut • Posterior temporal • Conduction • Repetition lost w/spared comprehension and expression • Arcuate Fasciculus
Astereogeneis and agraphesthesias:Cortical Dysfunction • Astereognosia: Patient cannot identify objects in hand • Agraphesthesia: Patient cannot identify a letter or number written in palm
Resting Vs. Intentional Tremors • Resting Tremors: • Basal Ganglia dysfunction • Parkinsonism • Wilson disease • Heavy Metal poisoning • Fear or anxiety • excessive physical activity or sleep deprivation • Alcoholism or alcohol or drug withdrawal states • Thyrotoxicosis • Poisoning • Intentional Tremors-Cerebellum • Occur during activity • Lesion affecting the superior cerebellar peduncle • Lead to functional disability
Location of Cranial Nerve nuclei in brainstem • CN 3 and 4 Nuclei: dorsal midbrain, ventral to the cerebral aqueduct • CN 6 nuclei: Dorsal and periventricular position in the PONS
Fasiculations are caused by which lesions • Lower Motor Neuron Lesions • Neuromuscular Junction
Definition of a Myelopathy • Cord Lesion or Compression
Motor system disorder onset timing relevance • Abrupt • Vascular disturbance • stroke • Toxic or metabolic disturbance • Subacute-onset of days to weeks • neoplastic • infective • inflammatory • Slowly • hereditary • degenerative • endocrinologic • neoplastic basis
Significance of the nature of progression of motor system • Progressive increase in motor deficit=continuing activity of the underlying process • Episodic: vascular or inflammatory origin • Steady: neoplastic disorder or motor neuron disease • Rapid fluctuations of symptoms over short periods: Myasthenia Gravis
S/s of compressive myelopathy • Motor, sensory or sphincter disturbances • Lesion above C5= either an ipsilateral hemiparesis or quadriparesis • Lesion in lower C/S: involvement of upper limbs is partial • Below T1: affect only the lower limbs on one or both sides • Unilateral involvement of the posterior columns of the cord leads to ipsilateral dysfunction below the level • Spinothalamic tract dysfunction in anterolateral columns: contralateral pain and temperature dysfunction below level. • Spasticity below level of lesion • Painful flexor or extensor spasms
Relationship of sensory symptoms and signs • Distribution of sensory symptoms and signs often suggest their site of origin in the neuraxis, and their temporal profile may suggest their cause • Sensory symptoms commonly PRECEDE sensory signs; the absence of signs in a patient w/sensory symptoms does NOT imply a psychogenic basis of symptoms
Characteristic of thalamic lesion • Burning irretractable pain • Pain in all of part of the contralateral half of the body • aggravated by emotional stress • develops during partial recovery fro ma sensory deficit caused by the underlying thalamic lesion • mild cutaneuos stimulations may produce unpleasant and painful sensations • Dejerine-Roussy syndrome • combination of sensory loss, spontaneous pain and perverted cutaneous sensation
Allodynia • Misrepresentation of a trivial tactile sensation as being painful
Corticobulbar tract define • The corticobulbar (or corticonuclear) tract is a white matter pathway connecting the cerebral cortex to the brainstem. The 'bulb' is an archaic term for the medulla oblongata; in modern clinical usage, it sometimes includes the pons as well. The word 'bulbar' therefore refers to the nerves and tracts connected to the medulla, and also by association to the muscles thus innervated, those of the tongue, pharynx and larynx. • The corticobulbar tract originates in motor cortex of the frontal lobe, just superior to the lateral fissure and rostral to the central sulcus. The tract descends through the genu of the internal capsule and a few fibers in the posterior limb of the internal capsule, as it passes from the cortex down to midbrain. In the midbrain, the internal capsule becomes the cerebral peduncles. The white matter is located in the ventral portion of the cerebral peduncles, called the crus cerebri. The middle third of the crus cerebri contains the corticobulbar and corticospinal fibers. The corticobulbar fibers exit at the appropriate level of the brainstem to synapse on the lower motor neurons of the cranial nerves.
Characteristics of peripheral nerve lesions • pain localized to region that is affected pathologically or confined to the territory of the affected nerve • burning quality, when mixed may accompany motor deficit • Painful peripheral neuropathies • diabetes • polyarteritis • alcoholic-nutritional deficiency states • entrapment neuropathies • COMPLEX REGIONAL PAIN SYNDROME TYPE 1 • pain follows injury but spreads beyond the site of trauma in a distribution that does not conform to that of an individual peripheral nerve, is greater than would normally be expected from the injury, and may progress w/time-sometimes to opposite limb. • Complex regional pain syndrome type 2 • also called Causalagia • designates the severe persistent pain, often burning that results from nerve trauma • exquisite tenderness • onset of pain anytime w/in the first 6 weeks or so after nerve injury • cause is uncertain, been attributed to ephaptic transmission between efferent sympathetic and afferent somatic fibers at the site of injury • In both cases, pain may be accompanied by swelling, increased seating , and vasoconstriciont of the affected extremity, allodynia, hyperalgesia, muscle atrophy and osteoporosis
Drugs associated w/Parkinsonism, causative and therapeutic • Causative-dopamine receptor antagonist • Antipsychotic drugs • phenothiazines • butyrophenones • metoclopramide • reserpine • tetrabenazine • Toxic substance • manganese dust • carbon disulfide • MPTP • Therapeutic-page 250 • Anticholinergic drugs • benztropine • trihexyphenidyle • Amantadine • Levodopa • Dopamine agonists • ergolides • MAO-B inhibitor • COMT inhibitor
Diseases of movement disorders : Wilson’s, drug induced Parkinsonism, Parkinson's, Gilles de la tourette syndrome • Wilson’s Disease • autosomal recessive disorder of copper metabolism • Kayser-Fleischer rings in the eye • large unbound copper enter circulation-deposit in tissues • present in childhood or young adult, average age is 11 • Neurological Findings • involves: caudate nucleus, putamen, cerebral cortex and cerebellum • resting or postural tremors • choreiform movements of limbs • facial grimacing • rigidity • hypokinesia • dysarthria • dysphagia • abonrmal posture • ataxia • Older patients • wild tremor • chorea • ballismus
Drug induced Parkinsonism • Drug Induced Parkinsonism • Dopamine-receptor antagonist • phenothiazine • butyrophenones • Antipsychotic drugs potent D2 receptor antagonists w/little anticholinergic effect • Tremor is uncommon • hypokinesia tends to symmetric • add anticholinergic drug to treat • trihexyphenidyl or benztropine • Levodopa is of no help
Parkinson • Pathology • loss of pigmentation and cells in substantia nigra • cell loss in globus pallidus and putamen • presence of Lewy Bodies • Pathogenisis • dopamine and acetylcholine are present in the corpus striatum • the balance between these 2 antagonistic neurotransmitters are disrupted because of dopamine depletion • Norepinephrine is also depleted • page 248 figure 7-2 • Clinical Findings • Tremors • most obvious • Rigidity • Hypokinesia • slowness of voluntary movement and reduction in automatic movement such as swinging the arms while walking • Abnormal Gait and posture • figure 7-3 page 248
gilles de la tourette syndrome • chronic multiple motor and verbal tics • unknown cause • symptoms before 21 • corticostriato-thalamo-cortical pathway seems to be involved • Clinical findings • first signs are motor tics 80% and vocal tics in 20% • vocal tics • grunts • barks • hisses • throat-clearing • coughing • coprolalila (cursing) • echopraxia imitation of others movements) • Palilalia(repetition of words or phrases) • Tics may be self mutilations • sever nail-biting • hair pulling • picking at the nose • biting the lips or tongue • Behavioral disorders • OCD • ADHD • Higher than normal left-handness or ambidexterity • DDX • Wilson's • Syndenham chorea • Bobble-head syndrome
Lenticular nucleus of the basal ganglia • Putamen+Globus Pallidum= Lenticulate Nucleus
Abnormal pinch sign in peripheral neuropathies • Anterior Interosseous nerve syndrome • poorly defined pain in the forearm • Motor branch of median nerve • no sensory complaints • inability to flex the terminal phalanges of the thumb and second finger resulting in an abnormal pinch sign • May be weakness of forearm pronation w/the elbow flexed • Flexor pollicus longus, radial part of the flexor digitorum profundus and the pronator quadratus
Common sites of peripheral nerve entrapment syndromes as well as the associated S/S’s -UPPER EXTREMITIES-Last row is a key!